Powder compacting apparatus for use with a mechanism for automatically measuring and dispensing unit quantities of dry powder

ABSTRACT

Powder compacting apparatus for use with a mechanism for automatically measuring and dispensing unit quantities of dry powder comprising means for transporting said dry powder through a tunnel having a progressively diminishing cross-sectional area wherein said dry powder is compacted to a uniform density immediately preceding and during the process of the measuring of the unit quantities of the dry powder.

United States Patent 191 Osterhaus Feb. 26, 1974 POWDER COMPACTINGAPPARATUS FOR [56] References Cited USE WITH A MECHANISM FOR UNITEDSTATES PATENTS AUTOMATICALLY MEASURlNG AND 2,297,244 9/1942 Pfahl100/010. 6

DISPENSING UNIT QUANTITIES OF DRY POWDER Inventor: Joseph C. Osterhaus,Port Jefferson,

Assignee: Eli Lilly and Company, Indianapolis,

Ind.

Filed: May 12, 1972 Appl. No.: 252,795

US. Cl 222/1, 222/194, 222/410,

- 4 100/177 Int. Cl B65b 13/20 Field of Search... 222/298, 410, 302,303, 168, 222/l,-367, 368, 370, 345; 100/177, DIG. 6, 43; l4l/l;425/427, 435

Primary ExaminerStanley l-l.- Tollberg Assistant Examiner-James M.Slattery Attorney, Agent, or Firm-Everet F. Smith; Ralph E.

Ernsberger [57] ABSTRACT said dry powder is compacted to a'uniformdensity immediately preceding and during the process of the measuring ofthe unit quantities of the dry powder.

19 Claims, 5 Drawing Figures PATENTEDFEBZ 61974 SHEEI 10F 3 FIG.2

PATENTEB FEBZ 6 I974 SHEET 3 BF 3 Fig. 5

POWDER COMPACTING APPARATUS FOR USE WITH A MECHANISM FOR AUTOMATICALLYMEASURING AND DISPENSING UNIT QUANTITIES OF DRY POWDER BACKGROUND F THEINVENTION 1. Field of the Invention This invention relates to a powdercompacting apparatus which operates in conjunction with a mechanism forautomatically measuring and dispensing unit quantities of dry powder.The mechanism for measuring and dispensing unit quantities of dry powderis believed to have been first described and claimed in US. Pat. No.

2,540,059. Subsequent patents have issued describing nous membranemember which permits the transfer of fluid in both directionsbutinhibits the movement of dry powder from one side to the other. Achamber is thus defined in one end of said cylinder and by adjusting thedistance of the foraminous membrane from the open end of the cylinderthe volume of the chamber can be changed. This chamber serves as avolumetric measure for dry powder. In operation, a plurality of suchdevices are arranged in an endless sequence, and in order that a unitquantity of dry powder can be measured in the chamber, said chamber isintroduced into the bed of dry powder and simultaneously a vacuum ispulled on the back side of the foraminous membrane. Dry powder is thendrawn into said chamber thus measuring a unit quantity of such powder.

One of the problems which has plagued the operation has been the lack ofuniformity of the density of the dry powder in the bed into which thechamber end of the cylinder is introduced. Consequently, the measurementof the quantity of dry powder has varied considerably from one device toanother.

Among the many uses to which this means for measuring unit quantities ofdry powder has been put is that of filling dry powder into two-piececapsules in the pharmaceutical industry. Other uses have includedmeasuring unit doses of dry powder for filling into ampoules, such asantibiotics which are later put into solution immediately priorto'injection. Another useful application of this method ofmeasuring unitquantities of -dry powder has been forv ordnance, where the powderchargegoing into small arms cartridges has been measured by this means.

In all of these applications it is desirable to maintain the variationfrom unit quantity to unit quantity at the very minumum. It is mucheasierto maintain this uniformity when the dry powder which is beingmeasured- Accordingly, it is an object of this invention to provide ameans for maintaining a uniformly densified dry powder at the locationin the powder bed where the devices which measure the unit quantitiesare introduced into such powder bed and said unit quantities of drypowder are drawn into the chambers of said devices.

Another object of this invention is to provide a means for compactingthe dry powder in conjunction with the powder reservoir which holds thedry powder from i which the unit quantities are measured.

SUMMARY It has now been discovered thata means for providing a uniformlydensitied dry powder bed from which unit quantities of dry powder aremeasured by the mechanism for automatically measuring and dispensingwith a progressively diminishing cross-sectional area through which thedry powder is transported wherein the dry powder in compacted to auniform density prior tothe measurement of said unit quantities ofdrypowder.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of thepowder compacting apparatus for use with a mechanism for automaticallymeasuring and dispensing unit quantities of dry powder.

FIG. 2 is a perspective view from the top of the rotatable circularpanportion of the powder compacting apparatus. Y I

FIG. 3 is a partial cut awayperspective view of the powder compactingapparatus showing the rotatable circular pan with the pan'coverspatially disposed thereabove. g

FIG. 4 is a cut away top plan view of the powder compacting apparatuslooking toward thebottom of the rotatable circular pan with theattendant side walls and tunnel wall arrangement which are a part of thepan cover. I

- FIG. 5 is a vertical cross-sectional side view of the powdercompacting apparatus showing the rotatable circular pan and the pancover spatially disposed thereabove.

DESCRIPTION or THE PREFERRED EMBODIMENTS In the followingdetaileddescription of the embodiments of this invention, reference is made tothe accompanying drawings. I

The powder compacting apparatus for use with a mechanism forautomatically measuring and dispensing unit quantities of dry powdercomprises: a) A rotatable circular pan having an essentially flatbottom, an integral circumferential sidewall extending upwardly at aboutfrom said bottom, an axial annular baffle affixed to and extendingupwardly at about 90 from said bottom, traction lugs affixed to theupper side and a rotatable shaft affixed to the under side of saidbottom.

b. An essentially flat cooperating circular pan cover stationarily,coaxially and spatially disposed above said pan having a first openingfor receiving the devices constituting the mechanism for automaticallymeasuring and dispensing unit quantities of dry powder, a second openingthrough which dry powder is introduced into said pan, vertical sidewalls defining a hopper affixed to edges of said second opening, acurvilinear vertical baffle having a progressively diminishing radiusmounted longitudinally in said hopper, and three sides of a four-sidedtunnel, the fourth of which is provided by said cooperating pan bottom.

c. Means provided for mounting said pan cover spatially above said pan.

d. Means provided for rotating said pan.

The novel powder compacting apparatus for use with a mechanism forautomatically measuring and dispensing unit quantities of dry powderwhich constitutes this invention operates as described and illustratedhereinafter.

I eter thereof. No insert would have been required but in Referring toFIG. ll, there is seen a rotatable circular pan 1. This rotatablecircular pan has an essentially flat bottom 2. An integralcircumferential sidewall 3 extends upwardly from said pan bottom at 90.Traction lugs 5 are affixed to the essentially flat bottom 2 of saidpan 1. These traction lugs 5 are affixed to the pan bottom 2 so thattheir longitudinal axes are parallel to a radius line of said panbottom-2. The traction lugs 5 have a longitudinal dimension of fromabout one-fifth to about three-fifths of the radius of said pan 1, awidth of from about one-sixteenth to about one-half inch and extendupwardly from the surface of the pan bottom 2 from about one-sixteenthto about three-eighths in'ch. Extending upwardly from the bottom 2 ofsaid pan 1 is an axial annular baffle 4 which rises to a height of fromabout one-fifth to about three-fourth of the height of the integralcircumferential sidewall 3 of said pan 1. This axial baffle 4 is fromone-sixteenth to about threeeighths inch wide and is positioned at adistance from the center point of said pan equal to from about onefifthto about two-fifths of the radius thereof.

In FIG. 1 there can be seen the various external elements of the.cooperating pan cover 7 which is stationarily, coaxially and spatiallydisposed above the circular rotating pan 1 illustrated in FIG. 2. Thecooperating circular pan cover is essentially flat although there aretwo openings in this flat top, one of which is quite extensive, but thisflat top extends completely around the perimeter of the pan cover. 7.

There is a first opening8 in pan cover 7 which serves for receiving thedevices of the mechanism for automatically measuring and dispensing unitquantities of I dry powder. This first opening 8 in said pan cover 7 isa curvilinear opening essentially in the form ofa arc of a circlepartially external to said pan cover 7. This are intersects theperimeter of pan cover 7 at points separated by from about 45 to about120. In FIG. 1 this first opening 8 is shown as an opening in an insert10 which forms a part of the flat surface of the pan cover 7. Firstopening 8 is slightly wider than the devices constituting saidmechanism. Turned-down ears on the flat top of a pan cover 7 are shownas supports 9 for insert 10. This is a preferred design but is notnecessary and could just as well have been worked out as an openingwhich started about one-fiftieth to about one-tenth of the radius ofsaid pan cover from the edge of the perimorder that a greater degree oflubricity could be pro- .vided for the movememt of the carrier for thedevices which are introduced into the bed of powder, carried in saidrotatable circular pan 1, it was found that an insert such as one thatcan be fashioned a material having a low coefficient of friction, suchas a polyfluorinated hydrocarbon polymer, wasa preferred design.

The pan cover 7 is shown in FIG. 1 with the sidewalls, tunnel top, andcurvilinear baffle in place. The second opening 11 is indicated as thatarea where the powder is introduced. The second opening 1], before theside walls, tunnel cover, and curvilinear baffel were installed actuallyencompassed a curvilinear area extending from the first transverse sidewall 14 around to the point at which the tunnel cover 21 meets the flattop of pan cover 7'just before the first opening 8 begins.

The second opening 11 in said pan cover 7 is a curvilinear openinghaving longitudinal curvilinear sides defined respectively by two arcs.The first (outer) arc has a radius of from about four to about seventimes the thickness of the side wall of said cooperating pan 1 less thanthe radius ofsaid pan cover 7. The second (inner) are has a radius offrom about one-fourth to about three-fifths of the radius of said pancover 7. The second opening 11 extends from about 120 to about 300 ofthe perimeter of said pan cover 7. The first and the second arcsrespectively are connected at the ends thereof by a first andsecond'transverse side which joins the two curvilinear arcs. An outercurvilinear member 12 is affixed to the outer edge of said curvilinearsecond opening 1 l, and projects both'upwardly and downwardly from saidedge at about'90. An inner curvilinear member 13 is affixed to the inneredge of said curvilinear second opening 11 and projects both upwardlyand downwardly about an equidistance with said outer curvilinear member12 at about from the edge of said opening 1 1. A first transverse member14 is affixed to the first transverse edge of said curvilinear opening11 and extends upwardly from said edge at about 90 to the same height assaid outer and inner curvilinear sidewall members and is affixed to oneend of both of said members. A second transverse member 15 connects saidouter and inner curvilinears members at 'a point from about one-fifth toabout fourvfifths of the distance from said first transverse side tosaid second transverse side respectively of said second opening 11. Thissecond transverse member 15 extends downwardly from the top edges ofboth the outer and inner curvilinear members, 12 and 13 respectively, toa point from about one-tenth to about three-fifths of the distance fromsaid second opening 11 to said top edges of said outer and innercurvilinear members. A curvilinear vertical baffle 16 is mountedlongitudinally in the hopper formed by the two curvilinear members 12and 13 and the two transverse members 14 and 15. The vertical baffle 16is affixed to the inside of the-outer curvilinear member 12 at a pointfrom about 10 to about 90 from the first transverse member 14. The otherend of the vertical baffle 16 is affixed to the second transverse member15 at a point from about one-twentieth to about one-fourth of thedistance from the outer curvilinear member 12 to the inner curvilinearmember 13. The transverse dimension of vertical baffle 16 is essentiallycoextensive with, the transverse dimension of curvilinear member l2.-

FIG. 1 also shows the top member 21 of a three-sided tunnel ofprogressively diminishing cross-sectional area. This top member 21 iscurvilinear in form and extends from ajunction with the bottom edge ofthe second transverse member and the outer and inner curvilinearmembers, 12 and 13 respectively, to a point at the second transverseside of the second opening 11 and at that point said top member 21 meetsthe flat top of the pan cover 7 and becomes integral therewith. From thepoint from where top member 21 originates, said member progressivelyslopes to a meeting with the flat top of the pan cover 7. In thisparticular section of the apparatus the outer curvilinear member 12declines from the point where the second transverse member 15 and thetop member 21 are joined thereto to a point where it meets the secondtransverse side of the second opening 11. Similarly, the innercurvilinear member 13 declines from the point where the secondtransverse member 15 and the top member 21 join with the two curvilinearmembers to a point where it meets the second transverse side of thesecond opening 11.

Also shown in FIG. 1 are rneans24 for mounting said pan cover 7spatially above said rotatable circular pan 1. These pan cover mountingmembers 24 are shown in FIG. 1 as being affixed to a stanchion 25 by astud bolt 26.

The heart of the design of the powder compaction apparatus of thisinvention resides in the tunnel through which the powder 'is transportedto effect a compaction prior to the time that the devices of themechanism for automatically measuring and dispensing unit quantities ofdry powder are introduced into the bed of dry powder. This compactingoperation is performed through the cooperation of the rotatable circularpan 1 and the pan cover 7. Pan cover 7 is stationarily, spatially, andcoaxially disposed above pan 1. Pan 1' rotates and in its rotation doesnot contact the pan cover. By virtue 'of the novel design of thisinvention the powder is not only compacted as it moves through thetunnel having a progressively diminishing crossse'ctional area, but inaddition. through the unique design of the baffels and sidewalls powderis held in the compacting apparatus in such a manner that it does notspill out in the area between the top edge of the rotatable circular pan1 and the top cover 7.

The basic elements which comprise the unique design of this apparatusare seen by refrring to FIG. 3. FIG. 3 is not only a partial cut awayperspective view of the apparatus but it is also illustrative of theinternal design of the apparatus and illustrates the various Iocationsof the elements which cooperate in this invention. The rotatablecircular pan '1 is shown with part of the sidewall 3 removed. Both theouter curvilinear member 12 and the inner curvilinear member 13 areshown extending below the top surface of pan cover 7 to a point near theupper surface of the bottom 2 of rotatable circular pan 1 but do nottouch the bottom of the said pan 1. Transverse member 14 extends only tothe topedge of said second opening 11. The second transverse member 15extends from the top of the two curvilinear members down to the pointwhere the tunnel top member 21 begins. The curvilinear longitudinalvertical baffle 16 extends only as far as said second transverse member15. The eccentric radius of vertical baffle 16 serves to continuouslymove the bulk of the powder away from the sidewall 3 of pan 1. At thepoint where said baffle terminates the powder then enters the tunnelwhich has a progressively diminishing crosssectional area.

As the rotatable circular pan 1 turns in a counter clockwise directionthe traction lugs 5 help to keep the dry powder moving in the directionthe pan is turning. As this dry powder is moved into the area of thetunnel it encounters resistance from the diminishing crosssectional areawhich is formed by the lower extension of the outer and innercurvilinear members 12 and 13 tothe point where the second transverseedge of the second opening 11 is located. A gradual slope on the toptunnel member 21 from the point of its origination to the point where itmeets the flat surface of the pan cover 7 also contributes to theprogressively diminishing cross-sectional area. And, as the powder movesthrough this area it meets greater and greater resistance and, ofcourse, becomes more and more compact. Extensions of thunder-the-surface sections of the outer and inner curvilinear members 12and 13 are provided. The extension 17 of the outer curvilinear member 12has a progressively diminishing radius as it proceeds from thepoint-where the second opening 11 terminates to a point essentiallycoinciding with the first transverse side of said second opening. Theextension 18 of the inner curvilinear member .13 disposed on the underside of said pan cover 7 proceeds at a progressively increasing radiusto a point essentially coinciding with the first transverse side of saidsecond opening 11. Moreover, the extension 18 of the inner curvilinearmember 13 is rnovably disposed on the under side of ,said pan cover 7and is illustrated at its maximum radius in FIG. 3.as 180. v l

The extension 1801 th inner curvilinear member 13 is anchored to theinner curvilinear member 13 at about the second transverse edge of thesecond opening 11 and is free to move laterally at the point where itterminates essentially at the first transverse side of said secondopening 11. A means for moving the terminal end of extension 18 isillustrated as 19 in FIG. 3. Also shown in FIG. 3 are two doctor blades22 and 23 respectively. Doctor blade 22 is affixed to the leading edgeof the underside projection of the outer curvilinear member 12and ismounted to contact the inner surface of the integral circumferentialside wall 3 of rotatable circular pan 1. The doctor blade 23 isaffixedto the outer curvilinear member 12 at a position approximately oppositethe location of doctor blade 22 and is provided for sweeping'powderwhich spills out from under the under-side projections of thecurvilinear member 12, extension 17, and baffle 16 back into themainstream of powder whichis being circulated in the rotatable circularpan 1.

In FIG. 4 there can be seen the disposition of the various under-sidemembers of the outer and inner curvilinear members and the extensionsthereof as well as the vertical baffle 16. In FIG. 4, the rotatablecircular pan 1 is shown turning in a counter-clockwise direction. Theillustration is looking down on the essentially flat bottom 2 of therotatable circular pan 1. The axial annular baffle 4 is shown inside ofthe under-side extension 18 of the inner curvilinear member 13. Thetraction lugs 5 are shown disposed inside of all of the under-sidemembers 12 and 17 and the baffle 16. While such a position for thetraction lugs 5 is a particularly desirable one, it is not essentialthat the lugs be so positioned as the lower projection of the side wallmembers and the baffle can terminate at a point above the top surface ofthe essentially flat bottom 2 of the rotatable circular pan 1 where thelugs can move underneath these extensions. However, it is preferred thatthe clearance of the bottom edges of these members and the top surfaceof the pan bottom should be as little as possible to minimize the amountof powder that is moved to the perimeter of the rotatable circular pan1.

While the outer and inner curvilinear members 12 and 13 respectively areshown as having essentially constant radii from their point of origin tothe position to which the underside extensions are attached such is notnecessary to the successful operation of this pow der .compactingapparatus and, as a matter of convience only, the radii were heldessentially constant to facilitate construction. The exact deviation ofthe vertical baffle 16 from a radius that is constant is of relativelylittle importance, since this particular baffle serves primarily to movethe powder away from the sides of the rotatable circular pan 1 and putit into a position to enter the tunnel in a favorable location. Thedecreasing radius shown for the extension 17 of'the outer curvilinearmember 12 is of no significant consequence but facilitates thecompacting operation. In practice the powder compacting apparatus couldbe operated effectively if this extension were essentially acontinuation of the radius of the outer curvilinear member 12. If thiswere the case then the increasing radius of the inner curvilinear memberextension 18 could be utilized to a greater extent. However, the twoextensions, 17 and 18 working in cooperation should provide for asignificantly diminishing cross-sectional area at the point where thedevices of the mechanism for automatically measuring and dispensing unitquantities are introduced.

The cross-sectional vertical view of the apparatus for compacting drypowder shown in FIG. depicts the relative relationship of thecurvilinear side wall members on the under side' of the surface of thepan cover 7. Each ofthe two curvilinear members 12 and 13 respectivelyproject below the under side of the pan cover 7 a distance which putstheir bottom edges just above the top surface of the essentially flatbottom of the rotatable circular pan l. The curvilinear vertical bafflel6 projects essentially the same distance below the under surface of thepan cover 7'. In order for the novel powder compacitng apparatus of thisinvention to be operable it is essential that the pan cover 7 bespatially disposed coaxially and stationarily above the rotatablecircular pan 1. The powder which is to be compacted is filled into therotatable circular pan through the second opening 11. The rotatablecircular pan 1 is rotated in a counter clockwise direction and as thedry powder is transported by the turning of the pan it moves through thetunnel which has a progressively diminishing crosssectional area and inthis movement is gradually compacted into a dry powder bed having-anessentially uniform bulk density. This compaction proceeds through asection of the pan cover cooperating with the rotatable circular pan andthe dry powder is compacted to a uniformly densified powder before thedevices of the mechanism for measuring and dispensing unit quantities ofdry powder are introduced into the bed of dry powder. lmmediatey thedevices of the mechanism for measuring and dispensing unit quantities ofdry powder are introduced into the bed of compacted dry powder there isan additional constriction applied to the moving dry powder bed in orderthat the voids which are 8 left in thebed as the devices are removedtherefrom can be filled in. This compaction and constriction of the drypowder leads to a minimum amount of variation in the weight of thepowder drawn into the chambers in successive devices. The devices whichconstitute the mechanism for measuring and dispensing unit quantities ofdry powder are described in US. Pat. application Ser. No. 215,606. Eachdevice consists essentially .edge of the first opening in the powdercompacting apparatus a cam means moves said device from its positionabove the opening 8 down and into the bed of dry powder. Vacuum isapplied to the back side of the foraminous membrane and a unit quantityof dry powder is drawn'into said chamber from the bed of dry powder.

The novel powder compacting apparatus of this invention provides auniformly densified bed of dry powder from which to measure unitquantities of dry powder. A uniformly densified bed of dry powder isbeneficial in holding the weight variation between unit quantities ofdry powder to a minimum.

What is claimed is;

l. A powder compacting apparatus for use with a mechanism forautomatically measuring and dispensing unit quantities of dry powdercomprising:

1. a rotatable circular pan having,

a. an essentially flat bottom,

b. an integral circumferential sidewall extending upwardly at about fromsaid bottom,

c. an axial annular baffle affixed to and extending upwardly at about 90from said bottom,

d. traction lugs affixed to the upperside of said bottom, and

e. a rotatable shaft affixed to the underside of said bottom;

2. an essentially flat cooperating circular pan cover stationarily,coaxially and spatially disposed above said pan having,

a. a first opening for receiving the devices consti-' tuting themechanism for automatically measuring and dispensing unit quantities ofdry powder,

b. a second opening through which dry powder is introduced into saidpan,

c. vertical sidewalls defining a hopper affixed to the edges ofsaid'second opening,

d. a curvilinear vertical baffle having a progressively diminishingradius mounted longitudinally in said hopper, and

e. three sides of a four-sided tunnel, the fourth of which is providedby said cooperatingpan bottom;

3. means for mounting said pan cover; and

4. means for rotating said pan.

2. The apparatus of claim 1 wherein said traction lugs are elongatedbars of a length of from about one-fifth to about three-fifths of theradius of said pan, a width of from about one-sixteenth to aboutone-half inch, extending from about one-sixteenth to about threeeighthsinch above the surface of said pan bottom, and are affixed to said panbottom with their longitudinal axes parallel to a radius line of saidpan.

3. The apparatus of claim 1 wherein said axial annular baffle extendsupwardly from the bottom of said pan to a height equal to form aboutone-fifth to about threefourth of the height of said sidewall of saidpan, is from about one-sixteenth to about three-eighths inchwide and ispositioned at a distance from the center point of said pan equal to fromabout one-fifth to about twofifths of the radius thereof.

4. The apparatus of claim 1 wherein said pan cover is essentially a flatplate having a diameter approximately equal to the outside diameter ofsaid pan with which it cooperates plus from about 2 to about 5 times thethickness of the sidewall of said pan.

5. The apparatus of claim 1 wherein said first opening in said pan coveris a curvilinear opening essentially in the form of an arc of a circlepartially external to said pan cover, said arc intersecting theperimeter of said pan cover at points separated by from about 45". toabout 120, said opening being slightly wider than the devicesconstituting said mechanism for measuring and dispensing unitquantitiesof dry powder, said mechanism which'are received therein, andbeginning and ending at points from about one-fiftieth to about onetenth of the radius of said pan cover from the edge of for from about120 to'about 300, and a first and second transverse side connecting therespectiveends of said curvilinear sides. I

7. The apparatus of claim 1 wherein said vertical side walls defining ahopper are comprised of I. an outer curvilinear member affixed to theouter edge of said curvilinear second opening, said curvilinear memberextending both upwardly and downwardly from said edge at about 90,

2. an inner curvilinear member affixed to the inner edge of saidcurvilinear second opening, said curvilinear member extending bothupwardly and downwardly from said. edge an equidistance with said outercurvilinear member at about 90,

3. a first transverse member affixed to the first transverse edge ofsaid curvilinear second opening, said transverse member extendingupwardly from said edge at about 90 and affixed to one end of both saidouter and inner curvilinear members,

4. a second transverse member connecting said curvilinear members andaffixed thereto at a point from about one-fifth to about four-fifths ofthe distance from said first transverse side to said second transverseside respectively of said second opening, said second transverse memberextending downwardly from the top edges of said outer and innercurvilinear members to a point from about one-tenth to aboutthree-fifths of the distance from said second opening to said top edgesof said outer and inner curvilinear members.

8. The apparatus of claim 7 wherein said outer and inner curvilinearmembers project downwardly from the undersurface of said second openinga distance essentially equal to the height of said sidewall of said panabove the uppersurface of said bottom thereof.

9. The apparatus of claim 7 wherein there is affixed to the portion ofsaid outer curvilinear member projecting downwardly from said secondopening doctor blades adapted to contact the inside of said sidewall ofsaid pan.

10. The apparatus of claim 1 wherein one end of said 'curvilinearvertical baffle mounted longitudinally in said hopper is affixed to theinside of said outer curvilinear sidewall member at a. point from about10 to about from said first transverse side wall member and the otherend of said baffle is affixed to said second transverse sidewall at apoint from about one twen tieth, to about one-fourth of the distancefrom said outer curvilinear sidewall member to said inner curvilinearsidewall member, the transverse, dimension of said baffle beingessentially coextensive with the transverse dimension of said outercurvilinear sidewall member.

11. The apparatus of claim 1 wherein the three sides of a four-sidedtunnel are defined by:

a. an essentially flat curvilinear top member, the first portion ofwhich is disposed between said outer and inner curvilinear members,originating at and affixed to the bottom edge of said second transversesidewall member and gradually sloping to a meeting with the top surfaceof said second opening and affixed to said sidewall members and saidopenings second transverse side, the second portion of said top memberbeing integral with the flat plate of said pan cover,

b. the outer curvilinear sidewall member extending upwardly to itsconnection with said top member, and an extension of that part of saidouter sidewall member disposed on the, underside of said pan cover, saidextension proceeding at a progressively diminishing radius-to a pointessentially coinciding with the first transverse side of said secondopening,

c. the inner curvilinear sidewall member extending upwardly to itsconnection with said'top member, and an extension of that part ofsaid'inner sidewall member disposed on the underside of said pan cover,said extension proceding at a progressively increasing radius to-a pointessentially coinciding with the first transverse side of said secondopen ing.

12. The apparatus of claim 10 wherein the extension of said innersidewall member-is movably disposed on the underside of said pan cover,said extension being affixed at its origin'to said inner sidewall memberand equipped at its terminal end with means for adjusting the locationof said terminal end to alter the distance between said inner sidewallmember extension and said outer sidewall member extension.

13. A powder compacting apparatus for use with a mechanism forautomatically measuring and dispensing unit quantities of dry powdercomprising:

1. a rotatable circular pan having an essentially flat bottom with anintegral circumferential sidewall extending upwardly at about 90 fromsaid bottom, said bottom having an axial annular baffle affixed theretoat position from about one-fifth to about two-fifths of the radius ofsaid pan from the center 1 1 thereof, said baffle rising from aboutone-fifth to about three-fourths of the height of said sidewall of saidpan and having a width of from about onesixteenth to about three-eighthsinch, further said bottom having affixed thereto a plurality ofelongated bars of a length of from about one-fifth to about three-fifthsof the radius of said pan and a width and a height of from aboutone-sixteenth to about one-half inch, said bars disposed with theirlongitudinal axes parallel to a radius line of said pan, and a shaftaffixed'to the bottom of said pan;

2. a circular, essentially flat pan cover cooperating with said pan,said pan cover stationarily, coaxially and spatially disposed above saidpan, said pan cover having a diameter slightly larger than said p 3. anessentially curvilinear first opening in said pan cover, said firstopening being essentially in the form of an arc ofa circle-external tosaid pan cover, said are intersecting the perimeter of said pan cover atpoints separated by from about 45 to about 120, said first opening beingslightly wider than the devices constituting said mechanism forautomatically measuring and dispensing unit quantities of dry powder;

4. an essentially curvilinear second opening in said pan cover, saidopening extending for from about 120 to about 300 of the perimeter ofsaid pan cover and having a width of from about one-fourth to aboutthree-fifths of the radius thereof;

5. outer and inner curvilinear sidewall members projecting both upwardlyand downwardly from the respective longitudinal edges of said openingand affixed thereto;

6. a first transverse sidewall member extending upwardly from the firsttransverse edge of said opening. affixed thereto and connected to oneend of said outer and inner curvilinear sidewall members;

7. a second transverse sidewall member disposed between said first andsecond curvilinear sidewall members and affixed thereto and extendingdownwardly from the top edges thereof to a point just above said secondopening;

8. a top tunnel member disposed between said outer and inner curvilinearsidewall members and affixed vthereto originatingat the bottom edge ofsaid second transverse sidewall member and extending at a gradual slopeto a meeting with the second transverse side of said second opening, andaffixed thereto;

9. a curvilinear extension ofsaid first curvilinear sidewall memberdisposed below the edge of said second opening extending at aprogressively decreasing radius to a point essentially coinciding withthe beginning of said second opening;

10. a curvilinear extension of said second curvilinear sidewall membermovably disposed below the edge of said second opening extending at aprogressively increasing radius to a point essentially coinciding 12-with the beginning of said second opening;

1 1. means for adjusting said progressively increasing radius of saidmovably disposed extension;

12. means for mounting said pan cover above said pan; and

13. means for rotating said pan.

14. A method of compacting dry powder to a uniform density in a bed fromwhich unit quantities are volumetrically measured comprising introducingsaid dry powder into the mouth of a tunnel having a progressivelydiminishing cross-sectional area and a circular pan, transporting amoving bed of said dry powder through said tunnel by continuously movingone side of said tunnel in the direction of the constriction therein toa point where volumetric measuring devices are introduced into saidmoving bed, continuing the transport of said moving bed of dry powderthrough said tunnel to the point where said measuring devices areremoved from said moving bed.

15. The method of claim 14 wherein the impetus for transporting saidmoving bed of dry powder through saidtunnel means is provided byrotating the circular pan, which comprises one side of said tunnel, inthe direction of the constriction in said tunnel.

16. The method of claim 15 wherein said impetus is augmented byequipping said circular pan with raised lateral lugs.

17. The method of claim 15 wherein said impetus is further augmented byoperating said circular pan as the bottom side of said tunnel.

18. The method of claim 14 wherein the compacting of said drypowder'from said point where said measuring devices are introduced intosaid dry powder bed to the point where said devices are removedtherefrom is effected by converging the stationary sides of saidcompacting means.

19. A method of compacting dry powder to a uniform density in a bed fromwhich unit quantities are volumetrically measured comprising:

a. introducing said dry powder into a reservoir oper ating inconjunction with a tunnel having a progressively diminishingcross-sectional area from its mouth to its outlet;

b. transporting said moving bed of said dry powder from said reservoirinto and through said tunnel by continuously moving one side of saidtunnel in the direction of said constriction therein;

c. continuing the transport of said moving bed of dry powder throughsaid tunnel to a point where volumetric measuring devices are introducedinto said moving bed;

d. converging the sides of said moving bed as said bed is transportedfrom the point where said measuring devices are introduced intosaid bedto the point where said devices are removed from said bed; and

e. releasing said moving bed from the progressively diminishingcross-sectional area of said tunnel.

1. A powder compacting apparatus for use with a mechanism forautomatically measuring and dispensing unit quantities of dry powdercomprising:
 1. a rotatable circular pan having, a. an essentially flatbottom, b. an integral circumferential sidewall extending upwardly atabout 90* from said bottom, c. an axial annular baffle affixed to andextending upwardly at about 90* from said bottom, d. traction lugsaffixed to the upperside of said bottom, and e. a rotatable shaftaffixed to the underside of said bottom;
 2. an essentially flatcooperating circular pan cover stationarily, coaxially and spatiallydisposed above said pan having, a. a first opening for receiving thedevices constituting the mechanism for automatically measuring anddispensing unit quantities of dry powder, b. a second opening throughwhich dry powder is introduced into said pan, c. vertical sidewallsdefining a hopper affixed to the edges of said second opening, d. acurvilinear vertical baffle having a progressively diminishing radiusmounted longitudinally in said hopper, and e. three sides of afour-sided tunnel, the fourth of which is provided by said cooperatingpan bottom;
 3. means for mounting said pan cover; and
 4. means forrotating said pan.
 2. an essentially flat cooperating circular pan coverstationarily, coaxially and spatially disposed above said pan having, a.a first opening for receiving the devices constituting the mechanism forautomatically measuring and dispensing unit quantities of dry powder, b.a second opening through which dry powder is introduced into said pan,c. vertical sidewalls defining a hopper affixed to the edges of saidsecond opening, d. a curvilinear vertical baffle having a progressivelydiminishing radius mounted longitudinally in said hopper, and e. threesides of a four-sided tunnel, the fourth of which is provided by saidcooperating pan bottom;
 2. The apparatus of claim 1 wherein saidtraction lugs are elongated bars of a length of from about one-fifth toAbout three-fifths of the radius of said pan, a width of from aboutone-sixteenth to about one-half inch, extending from about one-sixteenthto about three-eighths inch above the surface of said pan bottom, andare affixed to said pan bottom with their longitudinal axes parallel toa radius line of said pan.
 2. an inner curvilinear member affixed to theinner edge of said curvilinear second opening, said curvilinear memberextending both upwardly and downwardly from said edge an equidistancewith said outer curvilinear member at about 90*,
 2. a circular,essentially flat pan cover cooperating with said pan, said pan coverstationarily, coaxially and spatially disposed above said pan, said pancover having a diameter slightly larger than said pan;
 3. an essentiallycurvilinear first opening in said pan cover, said first opening beingessentially in the form of an arc of a circle external to said pancover, said arc intersecting the perimeter of said pan cover at pointsseparated by from about 45* to about 120*, said first opening Beingslightly wider than the devices constituting said mechanism forautomatically measuring and dispensing unit quantities of dry powder; 3.a first transverse member affixed to the first transverse edge of saidcurvilinear second opening, said transverse member extending upwardlyfrom said edge at about 90* and affixed to one end of both said outerand inner curvilinear members,
 3. The apparatus of claim 1 wherein saidaxial annular baffle extends upwardly from the bottom of said pan to aheight equal to form about one-fifth to about three-fourth of the heightof said sidewall of said pan, is from about one-sixteenth to aboutthree-eighths inch wide and is positioned at a distance from the centerpoint of said pan equal to from about one-fifth to about two-fifths ofthe radius thereof.
 3. means for mounting said pan cover; and
 4. meansfor rotating said pan.
 4. The apparatus of claim 1 wherein said pancover is essentially a flat plate having a diameter approximately equalto the outside diameter of said pan with which it cooperates plus fromabout 2 to about 5 times the thickness of the sidewall of said pan. 4.an essentially curvilinear second opening in said pan cover, saidopening extending for from about 120* to about 300* of the perimeter ofsaid pan cover and having a width of from about one-fourth to aboutthree-fifths of the radius thereof;
 4. a second transverse memberconnecting said curvilinear members and affixed thereto at a point fromabout one-fifth to about four-fifths of the distance from said firsttransverse side to said second transverse side respectively of saidsecond opening, said second transverse member extending downwardly fromthe top edges of said outer and inner curvilinear members to a pointfrom about one-tenth to about three-fifths of the distance from saidsecond opening to said top edges of said outer and inner curvilinearmembers.
 5. outer and inner curvilinear sidewall members projecting bothupwardly and downwardly from the respective longitudinal edges of saidopening and affixed thereto;
 5. The apparatus of claim 1 wherein saidfirst opening in said pan cover is a curvilinear opening essentially inthe form of an arc of a circle partially external to said pan cover,said arc intersecting the perimeter of said pan cover at pointsseparated by from about 45* to about 120*, said opening being slightlywider than the devices constituting said mechanism for measuring anddispensing unit quantities of dry powder, said mechanism which arereceived therein, and beginning and ending at points from aboutone-fiftieth to about one tenth of the radius of said pan cover from theedge of the perimeter thereof.
 6. The apparatus of claim 1 wherein saidsecond opening in said pan cover is a curvilinear opening having twolongitudinal curvilinear sides defined respectively by two arcs, thefirst (outer) of which has a radius from about 4 to about 7 times thethickness of the sidewall of said cooperating pan less than the radiusof said pan cover and the second (inner) of which has a radius of fromabout one-fourth to about three-fifths of the radius of said pan cover,said second opening extending for from about 120* to about 300*, and afirst and second transverse side connecting the respective ends of saidcurvilinear sides.
 6. a first transverse sidewall member extendingupwardly from the first transverse edge of said opening, affixed theretoand connected to one end of said outer and inner curvilinear sidewallmembers;
 7. a second transverse sidewall member disposed between saidfirst and second curvilinear sidewall members and affixed thereto andextending downwardly from the top edges thereof to a point just abovesaid second opening;
 7. The apparatus of claim 1 wherein said verticalside walls defining a hopper are comprised of
 8. a top tunnel memberdisposed between said outer and inner curvilinear sidewall members andaffixed thereto originating at the bottom edge of said second transversesidewall member and extending at a gradual slope to a meeting with thesecond transverse side of said second opening, and affixed thereto; 8.The apparatus of claim 7 wherein said outer and inner curvilinearmembers project downwardly from the undersurface of said second openinga distance essentially equal to the height of said sidewall of said panabove the uppersurface of said bottom thereof.
 9. a curvilinearextension of said first curvilinear sidewall member disposed below theedge of said second opening extending at a progressively decreasingradius to a point essentially coinciding with the beginning of saidsecond opening;
 9. The apparatus of claim 7 wherein there is affixed tothe portion of said outer curvilinear member projecting downwardly fromsaid second oPening doctor blades adapted to contact the inside of saidsidewall of said pan.
 10. The apparatus of claim 1 wherein one end ofsaid curvilinear vertical baffle mounted longitudinally in said hopperis affixed to the inside of said outer curvilinear sidewall member at apoint from about 10* to about 90* from said first transverse side wallmember and the other end of said baffle is affixed to said secondtransverse sidewall at a point from about one-twentieth to aboutone-fourth of the distance from said outer curvilinear sidewall memberto said inner curvilinear sidewall member, the transverse dimension ofsaid baffle being essentially coextensive with the transverse dimensionof said outer curvilinear sidewall member.
 10. a curvilinear extensionof said second curvilinear sidewall member movably disposed below theedge of said second opening extending at a progressively increasingradius to a point essentially coinciding with the beginning of saidsecond opening;
 11. means for adjusting said progressively increasingradius of said movably disposed extension;
 11. The apparatus of claim 1wherein the three sides of a four-sided tunnel are defined by: a. anessentially flat curvilinear top member, the first portion of which isdisposed between said outer and inner curvilinear members, originatingat and affixed to the bottom edge of said second transverse sidewallmember and gradually sloping to a meeting with the top surface of saidsecond opening and affixed to said sidewall members and said opening''ssecond transverse side, the second portion of said top member beingintegral with the flat plate of said pan cover, b. the outer curvilinearsidewall member extending upwardly to its connection with said topmember, and an extension of that part of said outer sidewall memberdisposed on the underside of said pan cover, said extension proceedingat a progressively diminishing radius to a point essentially coincidingwith the first transverse side of said second opening, c. the innercurvilinear sidewall member extending upwardly to its connection withsaid top member, and an extension of that part of said inner sidewallmember disposed on the underside of said pan cover, said extensionproceding at a progressively increasing radius to a point essentiallycoinciding with the first transverse side of said second opening. 12.The apparatus of claim 10 wherein the extension of said inner sidewallmember is movably disposed on the underside of said pan cover, saidextension being affixed at its origin to said inner sidewall member andequipped at its terminal end with means for adjusting the location ofsaid terminal end to alter the distance between said inner sidewallmember extension and said outer sidewall member extension.
 12. means formounting said pan cover above said pan; and
 13. A powder compactingapparatus for use with a mechanism for automatically measuring anddispensing unit quantities of dry powder comprising:
 13. means forrotating said pan.
 14. A method of compacting dry powder to a uniformdensity in a bed from which unit quantities are volumetrically measuredcomprising introducing said dry powder into the mouth of a tunnel havinga progressively diminishing cross-sectional area and a circular pan,transporting a moving bed of said dry powder through said tunnel bycontinuously moving one side of said tunnel in the direction of theconstriction therein to a point where volumetric measuring devices areintroduced into said moving bed, continuing the transport of said movingbed of dry powder through said tunnel to the point where said measuringdevices are removed from said moving bed.
 15. The method of claim 14wherein the impetus for transporting said moving bed of dry powderthrough said tunnel means is provided by rotating the circular pan,which comprises one side of said tunnel, in the direction of theconstriction in said tunnel.
 16. The method of claim 15 wherein saidimpetus is augmented by equipping said circular pan with raised laterallugs.
 17. The method of claim 15 wherein said impetus is furtheraugmented by operating said circular pan as the bottom side of saidtunnel.
 18. The method of claim 14 wherein the compacting of said drypowder from said point where said measuring devices are introduced intosaid dry powder bed to the point where said devices are removedtherefrom is effected by converging the stationary sides of saidcompacting means.
 19. A method of compacting dry powder to a uniformdensity in a bed from which unit quantities are volumetrically measuredcomprising: a. introducing said dry powder into a reservoir operating inconjunction with a tunnel having a progressively diminishingcross-sectional area from its mouth to its outlet; b. transporting saidmoving bed of said dry powder from said reservoir into and through saidtunnel by continuously moving one side of said tunnel in the directionof said constriction therein; c. continuing the transport of said movingbed of dry powder through said tunnel to a point where volumetricmeasuring devices are introduced into said moving bed; d. converging thesides of said moving bed as said bed is transported from the point wheresaid measuring devices are introduced into said bed to the point wheresaid devices are removed from said bed; and e. releasing said moving bedfrom the progressively diminishing cross-sectional area of said tunnel.